« on: 25/09/2018 02:15:18 »
If objects with non zero rest mass cannot travel faster than light then this means that gravity itself cannot make them travel faster than light. We are embedded in a universe with an enormous amount of matter surrounding us. All this matter generates gravitational fields. Our view of time is therefore not absolute. Which means our view of speed is not absolute. That is the first point. The second point is what is space? How do we reconcile speed through the vacuum. We can't use a measuring device, since we cannot be considered stationary with respect to anything other than our own 'inertial' frame. Especially not with respect to a vacuum. Therefore we can only determine speed via the shift in frequency of incoming signals. If you have no absolutely stationary markers to go by then signals is all you have. You then determine what you think is the distance and also the speed of an object by interpreting those signals. Since the shifting is pretty consistent it can be taken to show an expanding universe.
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